Breiten



DS. BREITENBACH.. RHEOSTAT.

APPucATloN mvfn muzi. 1920.

1,386,150. Patented m. 2,1921.

gru/vanto@ atto: nua

when moved into engagement with the posts 21 and 22 at the opposite limits ot its movement.

An indicating arm 28 is preferably secured to the knob 9 and is movable over a circular graduated scale 2d marked uponv t-he support 5 to assist in determining the position oi' the contact arm 18 with relation to the convolutions of the coil 20 whereby the resistance offered to the electrical current thereto may be approximated.

The wires of the circuit in which it is desired to interpose the rheostat are indicated b y the Lv numerals 26 and are connected, respectively, with the binding posts 16 and 2l and, the post 1G being electrically connected through the metallic parts of the rheostat to the contact arm 18 the electrical current is conducted thereto and passes therefrom into the convolutions of the coil 21, except when the rheostat is in off or on posii tion. When the switch arm is moved to on position, it contacts directly with a contact plate 25 electrically connected with the post 21 whereby the resistance coil 2O is cut out and the current flows directly :trom the contat-t arm 18 into the post 21. However, as the contact arm is moved away from the post 21 and successively engages with the several convolutions of the coil 20, the resista-iure to the passage for the electrical current is increased according tothe degree of resistancev of the material from which the coil is constructed and consequently any desired degree ot' resistance may be readily attained by proper adjustment o the arm 18. llhen the arm 18 is moved to oft position it disengages the last convolution of the coil 20 thereby breaking the circuit.

F rom the foregoing it is clearly evident that due to the novel arrangement of the several parts of the rheostat with relation to the sleeve G, the entire structure may be rigidly supported thereby necessitating merely the provision oi? an aperture in the supporting panel to facilitate application of the rheostat thereto. Furthermore, -due to the simple arrangement of the resistance coil 20, maximum area of the latter is presented to the atmosphere for radiating the heat generated incident to the passage of an electrical current therethrough thus insuring eitective cooling oit such resistance coil.

As will be read-ily apparent, the nut 11 may be dispensed with and in lieu thereof,

the plate 12 may be formed of adequate thickness to permit internal threading thereof, as suggested in Fig. d whereby the plate may be itted directly on the terminal of the sleeve 6.

What I claim is:

1. In a rheostat, an externally threaded supporting sleeve, a stem journaled in said sleeve, a nut threaded thereon, a supporting plate clamped between said nut and a support, opposed extensions formed on said supporting plate, laterally projecting threaded stems on said extensions,van insulated disk supported by said stems, spacing elements between said supporting plate and disk, a contact arm and a retaining nut positioned over the terminal of said stem, said disk having a circular, staggered 'series of apertures receiving the convolutions of a conductor, binding posts carried bysaid disk and a knob for turning said stemy and contact arm on said disk and over the conductor.

2. In a rheostat, a supporting sleeve, a stem journaled in said sleeve, 'a nut threaded thereon, a supporting plate clamped be-' tween said nut and a support, threaded stems on said extensions, an insulated disk supported by said stems and spaced from said supporting plate, a contact arm carried by said stem, said disk having a series of apertures receiving the convolutions of a conductor, binding posts carried by said disk and a knob for turning said contact arm on said disk and over said conductor.

3. In a rheostat, a supporting sleeve,.a

stem journaled in said sleeve, a clamping nut threaded thereon, a supporting plate having apertured, opposed extensions Yformed on said plate, screw threaded stems in said apertured extensions, an insulated disk rigidly supported on said'stems, spacing elements carried by said stems between said supporting plate and disk, a contact arm mo able with and on the outer extremity ot said stem, said disk having a series of staggered apertures receiving the convolutions of a conductor, binding posts on said disk and a knob for turning said stem and contact arm on said disk and over said conductor.

In testimony'whereot` I aiix my signature hereto.

DEREK S. BREITENBACH. 

